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.\" on Information Processing Systems.
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.\"     @(#)ferror.3	6.8 (Berkeley) 6/29/91
.\"
.\"
.\" Converted for Linux, Mon Nov 29 14:24:40 1993, faith@cs.unc.edu
.\"
.TH FERROR 3  2021-03-22 "" "Linux Programmer's Manual"
.SH NAME
clearerr, feof, ferror \- check and reset stream status
.SH SYNOPSIS
.nf
.B #include <stdio.h>
.PP
.BI "void clearerr(FILE *" stream );
.BI "int feof(FILE *" stream );
.BI "int ferror(FILE *" stream );
.fi
.SH DESCRIPTION
The function
.BR clearerr ()
clears the end-of-file and error indicators for the stream pointed to by
.IR stream .
.PP
The function
.BR feof ()
tests the end-of-file indicator for the stream pointed to by
.IR stream ,
returning nonzero if it is set.
The end-of-file indicator can be cleared only by the function
.BR clearerr ().
.PP
The function
.BR ferror ()
tests the error indicator for the stream pointed to by
.IR stream ,
returning nonzero if it is set.
The error indicator can be reset only by the
.BR clearerr ()
function.
.PP
For nonlocking counterparts, see
.BR unlocked_stdio (3).
.SH RETURN VALUE
The
.BR feof ()
function returns nonzero if the end-of-file indicator is set for
.IR stream ;
otherwise, it returns zero.
.PP
The
.BR ferror ()
function returns nonzero if the error indicator is set for
.IR stream ;
otherwise, it returns zero.
.SH ERRORS
These functions should not fail and do not set
.IR errno .
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.ad l
.nh
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.BR clearerr (),
.BR feof (),
.BR ferror ()
T}	Thread safety	MT-Safe
.TE
.hy
.ad
.sp 1
.SH CONFORMING TO
The functions
.BR clearerr (),
.BR feof (),
and
.BR ferror ()
conform to C89, C99, POSIX.1-2001, and POSIX.1-2008.
.SH NOTES
POSIX.1-2008 specifies
.\"https://www.austingroupbugs.net/view.php?id=401
that these functions shall not change the value of
.I errno
if
.I stream
is valid.
.SH SEE ALSO
.BR open (2),
.BR fdopen (3),
.BR fileno (3),
.BR stdio (3),
.BR unlocked_stdio (3)
.SH COLOPHON
This page is part of release 5.13 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%https://www.kernel.org/doc/man\-pages/.
